Android™ How to Program, Second Edition

MainActivity package Statement, import statements and Fields

Class MainActivity (Fig. 8.14) uses class FragmentTransaction (imported at line 6) to add and remove the app’s Fragments. MainActivity implements three interfaces:

• ContactListFragment.ContactListFragmentListener contains callback methods that the ContactListFragment uses to tell the MainActivity when the user selects a contact in the contact list or adds a new contact.

• DetailsFragment.DetailsFragmentListener contains callback methods that the DetailsFragment uses to tell the MainActivity when the user deletes a contact or wishes to edit an existing contact.

• AddEditFragment.AddEditFragmentListener contains callback methods that the AddEditFragment uses to tell the MainActivity ...